package algorithm.leetcode.medium;

/*
 在一个由 '0' 和 '1' 组成的二维矩阵内，找到只包含 '1' 的最大正方形，并返回其面积。
 */

/**
 * @author jack.wu
 * @version 1.0
 * @date 2020/12/17
 */
public class Question221 {

    public static void main(String[] args) {

    }

    public int maximalSquare(char[][] matrix) {
        int maxSide = 0;
        if (matrix == null || matrix.length == 0 || matrix[0].length == 0) {
            return maxSide;
        }
        int rows = matrix.length;
        int cols = matrix[0].length;

        int[][] dp = new int[rows][cols];

        for (int i = 0; i < rows; i++) {
            for (int j = 0; j < cols; j++) {
                if (matrix[i][j] == '1') {
                    if (i == 0 || j == 0) {
                        // 整个视图 右下角
                        dp[i][j] = 1;
                    }else {
                        dp[i][j] = Math.min(Math.min(dp[i - 1][j], dp[i - 1][j - 1]), dp[i][j - 1]) + 1;
                    }
                    maxSide = Math.max(maxSide, dp[i][j]);
                }
            }
        }
        return maxSide * maxSide;
    }
}
